Brake for strand handling apparatus



Jan. 19, 1954 T. T. BUNCH 2,666,289

BRAKE FOR STRAND HANDLING APPARATUS Filed Dec. 15, 1949 INVEN TOR 7. 7. BUNCH A T TORNE V Patented Jan. 19, 1954 BRAKE FOR HANDLING QAPPARATUS Tillman T.;'Bunch,-:Ashland, Mil, 'assignor 120 Western Electric, Company, Incorporated, New York, N. Y.,-- alcorporationof New York a 7 Application December 15, 1949, Serial No. 133,164

15 Claims. (01. 57 49) invention :relates to brakes for strand handling'apparatus, and more particularly to brakes for maintaining uniform tension onstrands being withdrawn from supply cops and for stopping the withdrawal of such strands.

In the manufacture of electrical conductors foruse in the communications art, certain types of conductors are advanced through an apparatus arranged to withdraw a strand material from one or more supply cops and serve it'spi'rallyaround the advancing core to form a covering on the conductor. The withdrawal of the strand from the-supply cop causes the cop to rotate with respect-to the strandwithdrawing means, whereby it usually is necessary to retard the relative rotation of the cop with a brakingforce sufficient to maintain uniform tension on the strand 'as it isexpended from a-full cop to empty cop.

'Due to the fact that the unwinding diameter of the cop is constantly decreasing as thestrand material is expended-from a full cop to an empty cop, the braking force must constantly decrease in order to maintain a uniform tension on the strand. An-accurate control of the strand {ten-' sign may be obtained byregulating the braking force retarding the rotation of the cop by-"the tension in the strand itself, whereby any changes in the strand tension adjusts the braking means directly so as to maintain the required tension on the strand. Itis further desirableto use the r braking means to stop the cop and the means withdrawing the strand from the cop when the v a strand, being withdrawn from the cop.

.A'brake for strand handling apparatus which embodies certain features of the inventi on',,,comprises a rotatable spindle'designed toreceivea strand supply cop, means for withdrawing thev strand from the cop at a predetermined rate and causing rotation of the cop, means for retarding the rotation of the spindle to tension the strand;

and means responsive to the tension on the strand for selectively controlling the spindle retarding means so as to -maintain uriiform tension on the strand as it is withdrawn from the-cop:

A clear understanding of the invention will be had from-the following detailed description of a specific embodiment thereof, when read in conjunction with the appended drawings in which like numerals designate identical parts throughout the several views, and, in which:

Fig. 1 is an enlarged, fragmentary, sectional view of a strand serving apparatus embodying certain features of the invention, and

Figs 2 'is an enlarged, vertical, sectional view taken along line 2-2 of Fig. 1.

Referring now to the drawings and more particularly to Fig. 1, there is shown a concentric type strand serving'machine of a type generally used in applying a textile orsimilar covering around an insulated or jacketed conductor. Only that portion of such a serving machine to which the invention is-directly related is shown in Fig. l, and, as shown, comprises an elongated shaft I'll suitably journalled in a bearing cartridge i I which is rigidly secured to the base of the serving machine, a portion of which is indicated by the numeral i2. A flange I5 is keyed to the portion of the shaft it adjacent to the bearing 1 l and has a thin metal cup It secured thereto by means of an annular cap I? secured to the flange 15 by a plurality of bolts one of which is shown in Fig. l, and indicated by the numeral 20. 7

"It is to beunderstood that the shaft It is. connected' to a suitable power means (not shown) which is arranged to rotate the shaft and the cup is attached thereto at a predetermined speed. The arrangement of the driving mechanism for the shaft is described fully in my copending application Serial No. 102,664, filed on or about July 1, 1949, hence, a detailed description of this mechanism is not given here.

The portion of the shaft Hi extending beyond the flange i5 is reduced in diameter to receive a tubular spindle 2| which is rotatably mounted on this portion of the shaft in by a plurality of needle bearings 22-42. The end of the spindle adjacent to the bottom of the cup I6 is provided with a hub 2 which fits neatly in a central bore 25, provided in the cap H. The hub portion 24 is provided with tween the ring 31 and acup-shaped ring 36 resting on the bottom of the counterbore-34 and keyed for rotation with the spindle 2|. The spindle 2| is designed to rotatably support a cop 31 having a supply of strand material 38 wound thereon in a fashion which permits it to be readily withdrawn therefrom and served around a core 40 being advanced through a central bore 4| provided in the shaft H: by suitable advancing means (not shown) The cop 3'! usually is wound on a cop tube 42 which is arranged to be keyed for rotation with the spindle 2i in any suitable manner, such as a plurality of longitudinal splines equally spaced about the periphery of the tubular spindle 2| and complementary ribs provided along the internal bor of the cop tube. The strand 38 is Withdrawn from the cop 31 and passes through a slot 43 provided in the cup and around the outside surface of the cup to an eye 45 through which the strand passes to an eye 46 provided on a piston rod 47 forming part of an air flow control poppet valve indicated generally at which is mounted inside the cup. The strand passes through the eye 45 and then upwardly as seen in Fig. 1 to a guide 56 secured at the lip of the cup and then moves angularly toward the core 40 passing through the central bore 4| of the shaft Ill.

Rotation of the cup l6 at a predetermined rate of speed, withdraws the strand from the cop 31 and serves it spirally around th advancing core 40 to form a suitable covering thereon. The Withdrawal of the strand causes the cop to rotate at a rate of speed greater than the speed of the cup due to the diameter of the cop with respect to the orbit of the rotating guide 5| attached to the cup I6.

The flange 33 forming part of the spindle 2| is provided with a brake ring 52 of suitable friction material. The needle bearings 222 2 permit the spindle 2! to move axially on the shaft l0 so that the brake ring 52 may engage the bottom of the counterbore 34, The springs 35-35 are designed to hold the spindle in its uppermost position so that normally the brake ring does not touch the bottom of the counterbore 34. When the ring 52 engages the bottom of the counterbore 34, the friction between th ring 52 and the surface of the counterbore 34-retards the rotation of the spindle 2| and the cop 31 carried thereby and tensions the strand 38 as it is withdrawn from the cop by the cup IS. The tension on the strand 38 must be maintained at a predetermined value as the strand is expended from a full cop to an empty cop to obtain a uniform covering on the core 40. However, as the diameter of the cop constantly decreases, the torque required to rotate the cop must decrease proportionately to maintain uniform tension on the strand throughout a serving operation from a full cop to an empty cop.

The cap I! is provided with a counterbore 53 adjacent to the flange 33 of the spindle 2| so as to form an annular chamber 54 between the upper side of the flange 33 and the bottom of the counterbore 53. Air under pressure from a suitable supply source (not shown) is admitted to the annular chamber 54, in a manner hereinafter to be described, to press the brake ring 52 against the-bottom oi the counterbore 34 with a force corresponding to th diameter of the cop, and thereby maintains a constant tension on the strand as it is withdrawn from th cop.

Air under pressure from a suitable supply source passes through an adjustable valv 63, an inlet pipe 55, a valve 56 having an adjustable cured to the shaft l0.

4 orifice therein and an outlet pipe 51 forming part of an air flow switch indicated generally at 58. The pipe 51 is connected to a threaded bore 60 provided in a ring 5| which is rigidly secured to the bearing H by a plurality of bolts, one of which is indicated generally by th numeral 62. The air passes through the bore fiti'to an annular groove provided in the ring BI and into an annular groove 56 provided in the flange l5 se- The air under pressure completelyfills the grooves 65 and 85 and passes from the groove 66 through a bore 6'! to a pipe I0 which transmits the air to an inlet port provided in the upperlend of a body ll of the poppet valve 50.

The air under pressure enters a tapered bore 12 provided in the body H and passes downwardly around an annular clearance formed between the tapered bore l2 and a piston 13 secured to the piston rod 4'! and siidably mounted on a guide rod 14 secured to the base of the body 1|.

through an outlet port and through a pipe 16 to a bore 1'! provided in the cap H. The bore 11 communicates with the counterbore 53 provided in the cap, whereby the air from the poppet valve 50 enters the annular chamber 54.

The presence of air under pressure in the annular chamber 54 exerts a pressure against the flange 33 provided on the spindle 2|, and thereby forces the brake ring 52 against the bottom of the counterbore 34. This pressure exerts a braking force on the spindl -in accordance with the pressure of the air maintained in the annular chamber. Since the spindle is rotating with respect to the cap ll, the bore in the cap I? provides a running clearance between the spindle and the cap which permits a predetermined leakage of air from the annular chamber into the cup l6, and, hence, into the atmosphere. Air also escapes around the clearance provided between the periphery of the flange 33 and the counterbore 34 and leaks under the friction ring 52 into the clearance between the counterbore and the upper portion of the shaft iii. To prevent air pressure from building up in the counterbore 3|], a plurality of holes l878 are provided in the shaft to permit the air which leaks into the counterbor 36 to escape through the central bore 4| or the shaft into the atmosphere. Due to the clearances between the bore 25 and the hub 24, and between the periphery of the flange 33 and the counterbore 34, the air from the supply source flows through an air flow switch 58 at a rate determined by the leakage of air through these annular clearances. The air at the supply source is maintained at pressure sufficient to maintain a substantial working pressure in the poppet valve and the annular chamber 54 in conjunction with the loss of air through the clearances in the chamber 54.

i Air under pressure from the pipe rt d passes through a pipe 88 into an air-actuated diaphragm apparatus 8| of the air flow switch 58 which may be mounted on a support it? suitably secured to the frame l2 of the serving machine. Air under pressure from the pipe 5! passes through a pipe 83 into an air-actuated diaphragm apparatus 84 also secured to the support 32 so as to be directly in line with the diaphragm apparatus 8|.

A post 85 is positioned between the diaphragm apparatus Bi and 84 to maintain a predetermined spacing between the apparatus. The dia-v Air escaping through th annular clearance between the piston and the tapered bore 72 passes sure: of. the air admitted to. the diaphragmscauses-a vertical movement of the rod 86. A collar 90. is adjustably ecured: to; the rod 86 by a. set; screw .9] and has a finger 92 extending there-- from to operate a sensitive switch :93 mountedcn .the support'82. The switch 93 preferably is provided with a normally closed contact (not shown)- wh-ich: is: connected in series with the: control circuit of the motor driving the shaft and thecup t6, so that a predetermined, downward; movement of. the. rod 86- opens the contact. of the switch 93 to deenergize. the. motor and ter-, minate therotation of the cup l6.

Operation Let it be assumed that the cap 31 is positioned on the spindle 2i, and that the strand 38. is threaded through the slot 43 and the. eyes 45' and 46, the guide 5| and attachedtothe. core 4H which has been threaded through the bore H- of the shaft l0. Air under pressure from a suit-- able supply source (not shown) passes through the pipe 55, the valve 56 and the pipe 51 of they air flow switch 58 to the grooves 55'and166-l The groove 65 is completely filled with air under pressure and the airpasses therefrom through an opening 61 and a pipe i0 to the inlet port provided in: the body H of the valve 59. The air passes through the annular clearance provided in the piston. 1.3 and the tapered bore 12 to an. outletport. 15 in. the body H, and. from; the outlet port through a pipe. 16 anda bore [1 tothe chamber 54. The air pressure in the. valve positions the piston 13 in its lowermost posi* tion within the. tapered, bore 1.2 of the body 1].

In this position, the piston permits the maximum escape of air-around the annular clearance between. the: piston and the tapered bore and,, hence, a maximum .air pressure in the annular chamber 54. This air pressure working against the upper side of the flange .33 moves the. spin dle axially on the shaft against the actions of. the-springs 3535 and presses. the brake ring 52 against the bottom .of the counterbore 34- with maximum force.

The motor driving the. shaft l0 and. the core advancing means (not shown) is. energized; torotate the cup l6 and advance the core. The retation of the cup withdraws thestrand. from the cop and serves it spirally around the core As the cup startsv to withdraw the strand 38 from the. cop 31, it rotates the spindle a ainst thev pressure on the brake ring: and produces. a braking force in excess of that which. is required to create the required, tension: on the strand .38 as. it. is served on the core Iii. This: excessive tension' on. the. strand immediately moves; the piston 13 in the tapered: bore 12 against therpressure of the air admitted to the body 11- so as to decrease the annular clearance between thevpis ton and the taperedbore. 12. This movementot the piston'reduces the "air pressure admitted. to theuannular chamber 5:4 to. such an extent. that the resulting force applied on the brake ring 5l-produces avbraking forceon the spindle which is sufilcient to create. the. required predetermined tension on the strand .38., This predetermined tension on the strand holds the piston 13 at an I intermediate point in the tapered bore 12 where the tension on the strand, plus the air pressure in the annular chamber 53, is equal to'the pressure of the air in the pipe 10; The pressure of thaalr-edmittedto the pipe-- may b' adiusted 6 by any conventional; pressure. regulatingsmeansa such as valve. 63 to obtain from the supply source, any desired tension on the. strand within reasonable limits.

Due to the. annular clearance provided between.

thebore 25 and the hub 24 of the spindle. 2-]. and.

between the flange 33 and. the. counterbore 34, ..a. slight. air leakage occurs from the annular champ her- 54 into the atmosphere. This air leakage creates a normal flow of air throughthe pipe 55..

the valve 56 and the. pipe 51 of the air flow switch;

58 and through the grooves 65 and-66 and the valve 50 to the. chamber 15.4. This air flow through the air flow switch 5.8- results inanair pressure in the diaphragm apparatus .8! substantially equal to the air pressure in the pipe 55. An air pressure substantially equal to that; in the; diaphragm apparatus 8|v also. occurs. in. the diaphragm apparatus .84. since the velocity of the air flow through. the. switch 58 is relatively-- low. 1

The differential between. the air pressure. ac ing on the diaphragm 8.1 and the air pressure acting onthe. diaphragm. 84 holds the finger 92' of the collar 9!]. at a predetermined position.

I 92, whereby its contact remains in; its normally closed position. With this normal air flow through the. switch .58, the valve 56 in thepipe.

line 5'? does. not disturb the pressure differential: between the diaphragm apparatus 81 and 8.4., As a result, the switch 93 is not actuated by the. finger 92' secured tov the rod;86.

As the cup It continues to-withdraw the. strand: from the cop and serve it, spirally around the core, the unwindingdiameter" of the-cop 3.1- eonstantly decreases. As; theunwinding diameter of the cop decreases, the length of the-lever arm from the tangential point, where the strand; leaves the cop to the center of rotation of the spindle constantly decreases. This. decreasing. length of the lever arm-requires a.cor-respondingv decrease in the-braking force applied on the spindle 2|. in order tomaintai-n a uniform tension on. the strand 38 throughout the unwinding. opera-- tionfrom a full coptov an empty cop. The effective braking radius of: the brake ring- :52 is: fixed; therefore, the braking force on the spindle must be decreased by continually decrease ing the pressureot the air in the annular chamber .54- as the. diameter .of the cop- 31 decreases to obtain uniform. tension on, the strand It has been stated. hereinabove,;that' when. the cup 16 is withdrawing the strand from, the .cop, thertension on the strand is approximately equal to the difference between. the air pressureyin the pipe .55 and. the. air pressure .in the-chamber. Therefore, the. increased tension in the strand resulting from the decrease in the unwinding diameter of the coptogether with the back pressure in the. valve 50 overcomes the pressure of the air supplied to the valve. .50 and moves: the piston T3-t0ward aportion of thextapered borehaving a smaller diameter. This movement hf. the piston reduces the annular clearance. and permit-s less air to escape from the. upper portion of the valve to the outletport 15, and, thereby reducesthe pressure of the air admitted to the annular chamber :54. This reduced .air pressure. in the chamber 54 reduces the braking force appliedon the spindle, and, consequently; reducles the tension takes place in verysmall incrementsi'be.

cause the change in the tension on the strand increases in very small amounts for very short periods of time. It is believed to be obvious from the above description, that as the unwinding diameter of the cop decreases, the strand operates the piston 13 in accordance with each decrease in the unwinding diameter of the cop so as to constantly decrease the air pressure admitted to the chamber 54 and thereby effect a corresponding decrease in the braking force on the spindle 2!. In this way the valve serves to maintain substantially uniform tension on the strand 38 as it is expended from a full cop to an empty cop by the cup l6 which serves it around the core All.

The valve 50 controls the braking force applied on the spindle in the manner described so long as the strand 36 does not break during the serving operation. Let is be assumed that during the serving operation, the strand 3B suddenly breaks, in which case, the parted strand allows the piston to drop to its lowermost position.

The piston in this position permits a maximum escape of air from the tapered bore 12 to the outlet port and results in a substantial increase in the air pressure in the chamber 54. The increased air pressure within the chamber 5& immediately stops the rotation of the cop and the spindle 2l with respect to the cup l6 driven by the shaft Ill. Butthe rotation of the cup it must be terminated substantially simultaneously with the cop 3'! to prevent the strand from unwinding from the cop and becoming entangled within the cup.

The sudden movement of the piston 13 to its lowermost position in the tapered bore of the valve 50, also creates a sudden increase in the velocity of the air flow in the pipe 5'? due to the sudden release of the air from the pipe 51 into the chamber 54. The valve 56 positioned between the diaphragm 8! and the diaphragm 84 provides a variable orifice in the air flow switch 58 which prevents the sudden release of the air from the pipe 5? a corresponding drop in its pressure from being restored immediately to the normal pressure differential between the diaphragms ill and 84 by the air supply source. Therefore, the sudden increase in the velocity of the air flow through the pipe 51 substantially reduces the pressure of the air acting on the diaphragm 84. This allows the diaphragm 8! to move the rod 85 so as to cause the finger 92 to actuate the switch 93 to open its contact and disconnect the motor (not shown) which is driving the shaft in from its power supply, whereupon the rotation of the cup I6 is terminated substantially simultaneously with the cop and spindle. Thus, when the strand 38 breaks during the serving operation, the release of the piston to its lowermost position effects an immediate stoppage of the spindle 2|, the cop 3'! and the cup l6.

' When a sufficient quantity of air passes through the valve 56 to bring the air pressure in the pipe 5'! up to air pressure in the pipe 55, the normal pressure differential between the diaphragms 8'! and 84 is restored'and the finger returns to its normal position with respect to the switch 33. This causes the switch 93 to resume its normal operating positon, but the motor driving the shaft I!) must be reenergized to place the apparatus in operation when the broken strand has been re paired.

While it has been shown that variations occur in the tension on the strand 38 as the diameter of the cop constantly decreases layerby layer, it should be understood that the strand tension jacent layer. All variations in the tension of the strand 38 operate the valve 50 in the manner described to vary the braking force on the spindle 2 i in accordance with the change in tension so as to maintain uniform tension on the strand as it is expended from a full cop to an empty cop.

While the above-described apparatus is particularly well adapted to maintain uniform tension on a strand being withdrawn from a strand supply cop during a serving operation, it may be readily modified to maintain uniform tension on various kinds of filamentary material employed in the manufacture of filamentary articles without departing from the spirit and scope of the invention.

What is claimed is:

1. A brake for tensioning strands withdrawn from a supply cop provided on strand handling apparatus, which comprises a support, a shaft positioned on the support, a spindle rotatably mounted on the shaft and designed to carry a cop containing a supply of strand material, means for withdrawing the strand from the cop and causing rotation of the cop by the paying on of the material therefrom, a brake element positioned'between one end of the spindle and the support, said spindlebeing free to move axially on the shaft, means for moving the spindle axially on the shaft and press the brake element against the support with a force sufficient to re tard the rotation of the spindle and tension the strand being withdrawn from the cop, and means responsive to the tension in the strand for selectively controlling the means urging the brake element against the support so as to maintain uniform tension on the strand as it is expended from a full cop to an empty cop.

2. A brake for tensioning strand material being withdrawn from a supply cop provided on strand handling apparatus, which comprises a shaft, a spindle rotatably mounted on the shaft and designed to carry a. cop containing a supply of strand material, means rotatable about the axis of the cop for withdrawing the strand material from the cop and causing rotation of the cop by the paying off of the material therefrom, a brake element mounted on the end of the spindle adjacent to a surface of the strand withdrawing means, said spindle being provided with a predetermined axial movement on the shaft, resilient means for holding the brake element out of engagement with the strand withdrawing means, means for moving the spindle on the shaft against the action of the resilient means and causing the brake element to engage the strand withdrawing means with a force sufficient, to retard the relative rotation of the spindle against the withdrawal of the strand and thereby tension the strand, and means responsive to the tension in the strand for selectively controlling the means urging the brake element against the strand withdrawing means so as to maintain uniform tension on the strand as it is expended from a full cop to an empty cop.

3. A brake for tensioning strands withdrawn item strand} handling apparatus: whfieir cont prisesa support, a shaft ositioned on; he- S1112: port} a spindle rotatah'l y positibned on the ee end of the shaft and d'esi'gned to oarry a eon-coritaining asupply of strand material; said 5 having" a surface in cl'oseprox mity-'tb-a sflrfafee' orthe su port; m'e'ansfbr wit'iini a'wingth'e rand from theoop' and causing'rotati ofiof ts fluid pressure aotnated 'r'ne'a hs fin o I surfaees'te engage each other withafo eient to" retard ther'otation of the" P t le and t n i n the t a d b in w tfidrai' ff cop; and means responsive to the t strand for sel'ectively eontroiiing the flu d t n io on h r nrfas.it swit di'a n fi' tfii: co'p.

i, A brake for strand handling apparatus", which comprises a rotatable s ndle esi n d to rial onthe free end thereof; means'for'vvithdraw mg the strandfrom theeopand causing rotat n of" the" cop by'the ayinaofiorthestrand n rial therefrom, a" brake elementmonnte'don e strand withdrawing means. adjacent tonne e'ndj dfthespindle, means for eausingairundefpres sure to urge the spindle" into" engagementwith the brake'ele nent with a; force sufficient re re tard" the tension in" thestrand" as-itis-with from the cop; and a" valve provided in the l pp m a a fi' 'i I' T QS UIG of $1 6 aircausing the spindle to engagethe brake-e19 merit", said valve being responsive to thetension in: the" strand so" as to regulate the airpressure acting n' h n tha it ma ntai s" a miformi ten'sion on the'stranda's'it' expendedi'ji'ohr a full cop to an empt'yco'p.

5; A brake for tensibni stran' ci materialwithdrawn from a snpp'lvcop' provided on strand hand ppara us; which comprises a sunport, a shaft vertically" positioned on thesupport; a spindle rotatabiyr ountbd onthe rre vendy' {the shaftand designed to carry a pop cont ing-a s pply o trand materi l, meansfo wit ing the strand from the cop and eausingrot oft p by he paying oflor-theist and the from, an annular brake element'seouredioh the spindle adjacent to' the" support; said spindle 1 ing freeto move axially enthe'sh'a'it sotha'tl't ebrake element may engage the support; means" for causing a fluid" under pressure to move the spindle on the shaft so tliatjitv presses the brake element against the support with a; three sumeient'to' retard the rotation of the spinal tension the strand being withdrawn" tro me eop, and a" valve provided the fluid" pressure system and arranged to be" operatedi By strand for selectively controlling the fiui'cl pr'f sure acting on the spindle-so'asto'maint u e fo m on n s r nd its ex n di'n 1 a run cop't o an empty cop.

rand: materia i 61A brake for tensioning'" st w hdraw f o u ply don p t e .07 a stran handlin apparatus; w ch wmprises a sifipp'ort, a shaft positioned on the a spindlerotatably'mounted'on theatre-en int a sha t a d d i ed" to car ya con .01 tamin suppl ofsti'afnd material; means fbfwithd w= is'th t a'n 'm a f om t e rn a 5 m rotation'of thec'op', an annular; I at"the base of the shaft supper-t1 g the slii'ndflf'e; said spindle having a flangeseeured ytherongfor rotation within the annular chamber; a brake element rovided on the annular fiangeiorj the.

1 0 on the" shaft to" permit the brake element to? engage the bottom of the annular chamber, nieans'fbr'adinitting air under pressure into the annulanehamhe'r to cause the-brake'element to engage thahottom' of the chamber with a force h ndlinaa paratus, wh com rise a s aft; a

V 1' rotatably'monnted on the'free'end of'the t a d' designed'to carry a cop containing a theoop for withdrawing the strand from the co n andeausing' rotation" of theeop'by thepaying eff g f't ,stiandtherefrom, a brake" elementm'oiint ed on one end of the rotatable spindle adjacent o the strand withdrawing means, said spindle ing. a predetermined axial movement on the shaft: means for causing air under" pressure to move the spindle axially of the shaft so thatitlie lpfraize ei'ement engages the strand withdrawing means with a force sufiie ient to retard the rela'- tive rotation ojfth'e spindle'andtension'the strand being withdrawn from the cop, and a valve provvided intii e air supply means having a iston siidahly' positioned therein for regulating" the pressureoi the air causing the brake eleinent'to rom a fi llfeopto" anempty cop.

82 A brake tor't'ensioning strand materialbeing Withdrawnfrom a supply cop provided'onstran'd handl-ihg apparatus, which comprises a shaft, a

- s indle rotatahl mounted on the free end of the shaft and designed to carry the cop" containing (a supply of strand" material; means rotatable about the axis" of the cop for Withdrawing the" strand mater-iaffi om the cop' andeausingrotation thereof by the payingjoff of the strand therefrom, a brake element positioned at the end'of the spindle adjaoent t'ow the strand withdrawing means, said spindlehaving a predetermined'axi'al movement onwthe shaft, means formoving the spindleaxially onflthe shaft thereby urging the brake element into engagement with the strand" withdrawing meansl tb retard" the relative'rotation of the spindle withwa braking; force suffioient' to tension the sti and'being withdrawn fromthe cop, and means responsiire tothe' tension onthe strand" for selectitelyoontrqlling the-hraking'force applied'on the spindle so .as tj'oimaintain uniform tension on the strandl a it is expended from a fulllcop to an empty 0 said. controlling means responsive to" the tension. ofthe strandbeing-so arranged" that ifthe strandl lireak's as it is withdrawn fromjtlje' co the controlling means is rendered mop'era tive; wherehy, the nrgin'gi means increases the braking force applied to" the spindle" to stop the-'- Qp1iinmediate1y' and prevent overrunning of the 9; a hrakefor strand handling apparatns, whi eh" e omprise's a shaft; a spindle rotatably mounted on the ireeend' of the shaftand de spindie,s'aiii s'pindlehavingsnmeientanialxnoi e snneate carryacop containing asupply of ybfstrandmaterial, means rotatable about aeeaase strand material, means rotatable about the axis of the cop for withdrawing the strand from the cop and causing rotation of the cop, a brake element positioned on the end of the spindle adjacent to the strand withdrawing means, said spindle being capable of axial movement on the shaft, means for moving the spindle axially on said shaft thereby causing the brake element to engage the strand withdrawing means and retard the relative rotation of the spindle with a braking force sufficient to tension the strand being withdrawn from the cop, means responsive to the tension on the strand for selectively controlling the means for moving the spindle axially on the shaft so as to maintain uniform tension on the strand as it is expended from a full cop to an empty cop, said tension controlling means being arranged to cause the brake element to substantially increase the braking force on the spindle and stop the rotation of the cop when the strand being withdrawn from the cop breaks, and means arranged to be operable when the strand tensioning means applies greater than a predetermined braking force on the spindle for stopping the strand withdrawing means simultaneously with the cop to prevent overrunning of the cop with respect to the strand withdrawing means.

10. A brake for tensioning strand material being withdrawn from a supply cop provided on strand handling apparatus, which comprises a shaft, a spindle rotatably mounted on the shaft and designed to carry a cop containing a given supply of strand material, means rotatable about the axis of the cop for withdrawing the strand material therefrom and causing rotation of the cop by the paying ofi of th material therefrom, a brake element mounted on the end Of the spindle adjacent to the strand withdrawing means having suflicient axial movement on the shaft so that the brake element engages the strand withdrawing means, means for causing a fluid under pressure to move the spindle axially of the shaft and causing the brake element to engage the strand withdrawing means and retard the relative rotation of the spindle with a force sufficient to tension the strand, means responsive to the tension in the strand for continuously regulating the rate of flow of the fluid acting on the spindle so as to vary the braking force thereon in ac: cordance with the constantly decreasing diameter of the cop and thereby maintain uniform tension on the strand as it is withdrawn from a full cop to an empty cop, and means responsive to a predetermined change of a rate of flow of the fluid acting on the spindle for terminating the rotation of the strand withdrawing means. 11. A brake for tensioning strand material being withdrawn from a supply cop provided on the strand handling apparatus, which comprises a rotatable shaft, a tubular spindle rotatably mounted on the free end of the shaft and designed to carry a cop containing a supply of strand material, a member secured for rotation with the shaft for withdrawing the material from the cop and causing rotation of the cop, a brake element positioned on the end of the spindle adjacent to the strand withdrawing member, said spindle being free to move axially on the shaft, means for causing air under pressure to move'the spindle axially of the shaft and press the brake element against the strand withdrawing member so that it retards the rotation of the cop with a braking force sufficient to tension the strand being withdrawn from the cop, a valve responsive to the tension in the strand for regulating the rate of flow of the air under'pressure acting on the spindle to vary the braking force applied thereon in accordance with the constantly decreasing diameter of the cop and thereby maintain uniform tension on the strand as it is expended from a full cop to an empty cop, said valve being arranged to substantially increase the pressure of the air acting on the spindle when the strand breaks so as to prevent overrunning of the spindle, an air flow switch provided in the air supply means so as to be actuated by a predetermined change in the rate of how of the air acting on the brake element, and means arranged to be actuated by the air flow switch for terminating the rotation of the strand withdrawing member when a strand breaks to prevent overrunning of the cop with respect to the strand withdrawing member.

12. A brake for tensioning strand material withdrawn from a supply cop provided on strand handling apparatus, which comprises a rotatable shaft, a spindle rotatably mounted on the free end of the shaft and designed to carry a cop containing a supply of strand material, a member secured for rotation with the shaft for withdrawing the strand from the cop and causing rotation of the. cop, a brake element mounted on the end of the spindle adjacent to the withdrawing means, said spindle having suficient axial movement on the shaft so that the brake element may engage the strand withdrawing member, a supply ofair under pressure, means for conducting air under pressure from the supply source to cause the spindle to move axially on the shaft so that the brake element retards the relative rotation of the spindle with a braking force sufficient to tension the strand being withdrawn from the cop by the withdrawing means, a valve positioned in the air conducting means and responsive to the tension in the strand being withdrawn from the cop for continuously regulating the pressure of the air acting on the spindle so as to vary the braking force on the spindle in accordance with the constantly decreasing diameter of the cop and maintain uniform tension on the strand as it is expended from a full cop to an empty cop, and an air flow switch including a pair of air-actuated diaphragms connected together so as to be subject to the pressure of the air in the conducting means ahead of the valve operated by the strand tension, said arrangement of the air diaphragms producing a normal operating pressure differential between the diaphragms, an orifice positioned between the diaphragms to restrict the rate of flow of air through the conducting means joining the diaphragrns, and means arranged to be actuated by the air flow switch when the pressure differential between the diaphragms is not normal to terminate the rotation of the strand withdrawing means, said valve controlled by the strand tension being arranged to substantially increase the rate of flow and the pressure of the air acting on the spindle when the strand breaks to stop the cop immediately, said operation of the valve due to the breakage of the strand substantially increasing the rate of flow of air between ene of the diaphragms and the valve and changing their normal pressure differential sufliciently to operate the switch and terminate the operation of the strand withdrawing means simultaneously with the stoppage of the cop.

13. A brake for tensioning strand material withdrawn from a supply cop on a strand handling apparatus, which comprises a rotatable 13 shaft, a spindle rotatably mounted on the free end of the shaft designed to carry a cop containing a supply of strand material, a membersecured to the shaft for rotation therewith for withdrawing the strand from the cop and causing rotation of the cop, said spindle having: a flange secured on one end thereof, a brake element secured on the annular flange of the spindle, an annular chamber formed in the strand serving member to receive the flange on the spindle and the brake element, said spindle having sufficient axial movement on the shaft so that the brake element may engage the bottom of the annular chamber, a supply of air under pressure, means for conducting the air under pressure from the supply source to the annular chamber, said air pressure in the annular chamber acting onthe flange and moving the spindle so that the brake element engages the bottom of the chamber and retards the rotation of the spindle with a braking force sufficient to tension the strandbeing withdrawn from the cop, a valve positioned on the strand serving member and actuated by the tension in the strand for regulating the pressure of the air in the annular chamber so as to maintain uniform tension on the strand as itjis expended from a full cop to an empty cop, said annular chamber having a leakage path between the strand serving member and the spindle whereby a predetermined flow of air occurs throughout the air conducting means, an air flow switch comprising a pair of air-actuated diaphragms positioned in the air conducting means so that each diaphragm is subject to the air pre'ssure in the conducting means, a variable orifice provided in the air conducting means between the diaphragms, said valve being arranged to sub-. stantially increase the rate of flow of air through i the air conducting means when the strand breaks to stop the rotation of the cop, means arranged to be actuated by the air switch for terminating the rotation of the strand serving member, said variable orifice serving to maintain an unbalanced air pressure in the air diaphragms for a period of time suflicient to permit the air flow switch to operate the switch and terminate the rotation of the strand withdrawing member when the strand breaks to prevent overrunning of the cop with respect to the strand withdrawing member.

14. A brake for tensioning strands withdrawn from a supply cop provided on strand handling apparatus, which comprises a support, a shaft positioned on the support, a spindle rotatably mounted on the shaft and designed to carry a cop 5 containing a supply of strand material, means for withdrawing the strand from the cop and causing rotation of the cop by the paying off of the material therefrom, a brake element positioned between one end of the spindle and the support, said spindle being free to move axially on the shaft, means for moving the spindle axially on the shaft and press the brake element against the support with a force suflicient to retard the rotation of the spindle and tension the strand being withdrawn from the cop, means responsive to the tension in the strand for controlling the means urging the brake element against the support so as to maintain uniform predetermined tension on the strand as it is expended from a full cop to an empty cop, and means for selectively adjusting the value of the predetermined tension on the strand while the strand handling apparatus is in operation.

15. A brake for tensioning strands withdrawn from strand handling apparatus, which comprises a support, a shaft positioned on the support, a spindle rotatably positioned on the free end of the shaft and designed to carry a cop containing a supply of strand material, said spindle having a surface in close proximity to a surface of the support, means for withdrawing the strand from the cop and causing rotation of the spindle, fluid pressure actuated means for causing the surfaces to engage each other with a force sufilcient to retard the rotation of the spindle and to tension the strand being withdrawn from the cop, means responsive to the tension on the strand for controlling the fluid pressure actuated means so as to maintain uniform predetermined tension on the strand as it is withdrawn from the cop, and means for selectively adjusting the value of the predetermined tension on the strand while the strand handling apparatus is in operation.

TILLMAN T. BUNCH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 859,216 Hadley July 9, 1907 2,098,422 Keen et a1 Nov. 9, 1937 2,134,561 Keyes Oct. 25, 1938 2,253,740 Van Hook Aug. 26, 1941 2,332,655 Miles Oct. 26, 1943 2,353,727 Howard July 18, 1944 2,388,982 Leithiser Nov. 13, 1945 2,430,358 Merwin et a1 Nov. 4, 1947 FOREIGN PATENTS Number Country Date 411,994 Great Britain June 21, 1934.- 

